Recently, a crawler type traveling device capable of realizing a stable traveling operation is used in a working vehicle traveling on a soft ground or an irregular ground such as a slope. Then, there is known a technology that improves ground contact performance of a crawler traveling device by connecting a pair of right and left crawler traveling devices to each other through an equalizer bar and suspending the equalizer bar on the vehicle body frame to be rotatable about the longitudinal direction serving as an axis so that the crawler traveling device moves to follow a slope of a ground in the horizontal direction (for example, Patent Literature 1). Further, there is known a technology in which a lower portion of a chassis frame turnably equipped with an upper turning body including a working tool and a cab is provided with four telescopic arm each having a travel crawler traveling device provided at a lower end thereof and four telescopic arms move in a telescopic manner to follow an unevenness portion of an irregular ground so that the upper turning body is kept horizontally (for example, Patent Literature 2).